// Copyright (c) 2012-2016 The Bitcoin Core developers
// Copyright (c) 2017-2019 The Raven Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include "consensus/merkle.h"
#include "merkleblock.h"
#include "serialize.h"
#include "streams.h"
#include "uint256.h"
#include "arith_uint256.h"
#include "version.h"
#include "test/test_raven.h"

#include <vector>

#include <boost/test/unit_test.hpp>

class CPartialMerkleTreeTester : public CPartialMerkleTree
{
public:
    // flip one bit in one of the hashes - this should break the authentication
    void Damage()
    {
        unsigned int n = InsecureRandRange(vHash.size());
        int bit = InsecureRandBits(8);
        *(vHash[n].begin() + (bit >> 3)) ^= 1 << (bit & 7);
    }
};

BOOST_FIXTURE_TEST_SUITE(pmt_tests, BasicTestingSetup)

    BOOST_AUTO_TEST_CASE(pmt_test)
    {
        BOOST_TEST_MESSAGE("Running PMT Test");

        SeedInsecureRand(false);
        static const unsigned int nTxCounts[] = {1, 4, 7, 17, 56, 100, 127, 256, 312, 513, 1000, 4095};

        for (int i = 0; i < 12; i++)
        {
            unsigned int nTx = nTxCounts[i];

            // build a block with some dummy transactions
            CBlock block;
            for (unsigned int j = 0; j < nTx; j++)
            {
                CMutableTransaction tx;
                tx.nLockTime = j; // actual transaction data doesn't matter; just make the nLockTime's unique
                block.vtx.push_back(MakeTransactionRef(std::move(tx)));
            }

            // calculate actual merkle root and height
            uint256 merkleRoot1 = BlockMerkleRoot(block);
            std::vector<uint256> vTxid(nTx, uint256());
            for (unsigned int j = 0; j < nTx; j++)
                vTxid[j] = block.vtx[j]->GetHash();
            int nHeight = 1, nTx_ = nTx;
            while (nTx_ > 1)
            {
                nTx_ = (nTx_ + 1) / 2;
                nHeight++;
            }

            // check with random subsets with inclusion chances 1, 1/2, 1/4, ..., 1/128
            for (int att = 1; att < 15; att++)
            {
                // build random subset of txid's
                std::vector<bool> vMatch(nTx, false);
                std::vector<uint256> vMatchTxid1;
                for (unsigned int j = 0; j < nTx; j++)
                {
                    bool fInclude = InsecureRandBits(att / 2) == 0;
                    vMatch[j] = fInclude;
                    if (fInclude)
                        vMatchTxid1.push_back(vTxid[j]);
                }

                // build the partial merkle tree
                CPartialMerkleTree pmt1(vTxid, vMatch);

                // serialize
                CDataStream ss(SER_NETWORK, PROTOCOL_VERSION);
                ss << pmt1;

                // verify CPartialMerkleTree's size guarantees
                unsigned int n = std::min<unsigned int>(nTx, 1 + vMatchTxid1.size() * nHeight);
                BOOST_CHECK(ss.size() <= 10 + (258 * n + 7) / 8);

                // deserialize into a tester copy
                CPartialMerkleTreeTester pmt2;
                ss >> pmt2;

                // extract merkle root and matched txids from copy
                std::vector<uint256> vMatchTxid2;
                std::vector<unsigned int> vIndex;
                uint256 merkleRoot2 = pmt2.ExtractMatches(vMatchTxid2, vIndex);

                // check that it has the same merkle root as the original, and a valid one
                BOOST_CHECK(merkleRoot1 == merkleRoot2);
                BOOST_CHECK(!merkleRoot2.IsNull());

                // check that it contains the matched transactions (in the same order!)
                BOOST_CHECK(vMatchTxid1 == vMatchTxid2);

                // check that random bit flips break the authentication
                for (int j = 0; j < 4; j++)
                {
                    CPartialMerkleTreeTester pmt3(pmt2);
                    pmt3.Damage();
                    std::vector<uint256> vMatchTxid3;
                    uint256 merkleRoot3 = pmt3.ExtractMatches(vMatchTxid3, vIndex);
                    BOOST_CHECK(merkleRoot3 != merkleRoot1);
                }
            }
        }
    }

    BOOST_AUTO_TEST_CASE(pmt_malleability_test)
    {
        BOOST_TEST_MESSAGE("Running PMT Malleability Test");

        std::vector<uint256> vTxid = {
                ArithToUint256(1), ArithToUint256(2),
                ArithToUint256(3), ArithToUint256(4),
                ArithToUint256(5), ArithToUint256(6),
                ArithToUint256(7), ArithToUint256(8),
                ArithToUint256(9), ArithToUint256(10),
                ArithToUint256(9), ArithToUint256(10),
        };
        std::vector<bool> vMatch = {false, false, false, false, false, false, false, false, false, true, true, false};

        CPartialMerkleTree tree(vTxid, vMatch);
        std::vector<unsigned int> vIndex;
        BOOST_CHECK(tree.ExtractMatches(vTxid, vIndex).IsNull());
    }

BOOST_AUTO_TEST_SUITE_END()
